Flying U ranch owner Sam Talbot is killed by a fall from a horse.
St. Louis reporter Connie Edwards (Dale Evans) comes to check a rumor that he might have been murdered.
She goes to Roy Rogers, editor of the local newspaper, and he takes her to the reading of Talbot's will.
The ranch is left to Talbot's 12-year-old ward, Duke Lowery (Lanny Rees), much to the dismay of Talbot's niece, Jan Holloway (Carol Hughes).
After some attempts on Duke's life, Roy finally proves that Jan, Steve McClory (George Meeker) and coroner Jim Judnick (Arthur Space) had Talbot killed and are conspiring to do the same for Duke, making Jan the last heir.